Introduction

rc1

There have been regressions since 2.6.39.

The kernel hangs waiting for the sd/mmc card.

Enabling USB results in very ugly kernel oops.

Something is amuck with the wl21xx support.

rc2

Looks like Tony Lindgren's pull request to Linus missed the release of -rc2 by a couple of hours, so no fixes got into -rc2.
We will have to wait a week or so for -rc3, an expanded mmc fix for the issue is included.

rc3

Well, -rc3 is out and the mmc issue is fixed, but the revert of commit 7e6502d577106fb5b202bbaac64c5f1b065e6daa is still necessary to let the kernel boot with ehci enabled, however something else has broken as the USB ethernet is not functional and DVI doesn't work either. It is of interest to note that there have been massive changes to wl12xx to support ap functionality, as well as massive changes in drivers/video/omap2/dss/.
So it seems that -rc3 is a further regression from 2.6.39.

rc4

-rc4 has fixed many of the issues introduced in rc3, however no progress with the issues introduced in 3.0.

The reversion of commit 7e6502d577106fb5b202bbaac64c5f1b065e6daa is still necessary.

The I2C patch is still necessary.

The DVI patch is still necessary.

The wl21xx still has problems, no temp fix available (yet).

rc5

-rc5 has quite a few changes to omap4 code, but no additional fixes from -rc4

The reversion of commit 7e6502d577106fb5b202bbaac64c5f1b065e6daa is still necessary.

The mmc patch is still required, as are the dvi patch (if you want anything other than 640x480) and the i2c patch.

Building

Building 3.0-rc1,-rc2,-rc4, or -rc5 is basically the same as How to build 2.6.38 kernel, but of course you need the -rc1/2/4/5 sources. The omap2plus_defconfig works once the mmc patch is applied (for -rc1 & -rc2). config.3.0-rc2.1 works for the reverted commit, mmc patch, dvi patch and i2c patch. For -rc5 with patched sources use config.3.0-rc5.1.

MMC Patch

A patch is available which addresses the mmc issue noted above, it is no longer required for -rc3,-rc4 or -rc5: